Nick Scoville

Early Universe Galaxy and AGN Evolution

The major focus of my current research is the Cosmic Evolution
Survey (COSMOS) which focuses on the assembly and evolution of
galaxies and their central black holes (AGN) at redshifts from
0.2 to 6. This survey was started in 2004 with 600 orbits on HST
to image a 2 square-degree equatorial field, but it now includes
imaging and spectroscopy from virtually every large space and
ground-based telescope. Over a million galaxies are detected out
to redshift 6 when the universe was only a billion years old; the
survey is therefore equivalent to the Sloan survey of the local
universe but covering the period of maximum galaxy and AGN evolution
at z > 1.

My major personal interest has been in mapping the large scale
structures for the first time at high redshift and relating galaxy
properties and their rates of evolution to their environments. The
dark matter structures ￼have been mapped in COSMOS using weak lensing,
while the baryonic matter distribution is revealed by the overdensity
of galaxies. We are now finding that the masses of the galaxies and the
ages of their stellar populations are strongly correlated with the large
scale structures. Such environmental correlations were anticipated from
local universe studies I had been involved in earlier which showed
greatly enhanced star formation rates in merging and interacting IR
luminous galaxies. However, in the nearby universe these activities
are relatively rare.

In the future, I look forward to extending such work into the epoch
of reionization using the on-coming ALMA, TMT and JWST facilities. These
facilities will of course provide better sensitivity – more importantly
they will provide the spatial resolution on high redshift galaxies
needed to really understand the physical processes most important to
the early assembly and evolution.